Complete electrical failure - intermittent

[Worty]

Hi all

The '62 GF A10 has a strange problem - as follows:

Battery is a brand new, charged Westco AGM item which works very well.  The problem I have is  that I regularly lose all the electrics which momentarily come back on occasionally then go off.  I know the battery is good from testing and the fact that the horn works very well when the power returns.  Most recently, I can get the horn but not the lights, then all goes dead again.  I've checked as much of the wiring as possible but it all looks intact??  Apart from a broken wire somewhere, I'm at a loss - any ideas.

NB:  The horn buzzes as if it's trying to work.  If it's an earth problem, could I have details on how to do this successfully.

Cheers

[duTch]

 dodgy switch?

[polly]

Its most probably a problem between the battery and the brown wires to the ammeter or maybe the ammeter its self.

[polly]

If correctly wired that is.....the only wired unit thats just battery and earth is the stop light  .so I would imagine that if when this happens [the complete failure] the stop light still works then chances are its not an earthing problem  . Its possible its wired the norton way and the horn is direct from the battery and not via the ammeter ,if this [the horn and stop light] are both part of the failure then its an earth problem.

[a10 gf]

Some quick thoughts :O)

How does the ammeter behave when the blackout occurs? Going to zero = fault (open circuit) after ammeter, going heavily in drain = short somewhere.

When power ok, wriggle and bend cables, switches etc all around the bike and see if you can forcefully trigger the fault, to locate to some specific area to investigate further.

Drive with a multimeter (V) connected to the battery and see if the blackout comes with a sudden voltage drop (= probably some short to frame somewhere, or some serious internal battery failure)

The elimination method and see if the problem stops or continues:
- disconnect A from the regulator (with a fully charged battery, drive for a while)
- short the ammeter
- connect extra cable from battery to ammeter
etc etc, experiment (following the wiring diagram) until the culprit is identified.

[duTch]

 In addition to a possible dodgy switch, what regulator do you have? I ask because I had a similar issue not so long ago.

[Worty]

Cheers all, loads to respond to:

1.  Have checked switch and all seems to be good there.
2.  Regulator is solid state +ive earth.
3.  Ammeter does not move unless lights come on when it drops as it should - ammeter is brand new also.
4.  Have wiggled wires all over but cannot get the fault to show consistently.  I've done this by keeping my finger on the horn and going round the wiring until horn sounds.  Unfortunately, I just can't get one spot.
5.  The stop light does not work when electrics are off.

Although this has happened before, it's not been quite as catastrophic as now.  I know people have additional earths here and there and that's not a problem so long as I can diagnose correctly.

One other possible symptom - when the horn eventually sounds and I switch the lights on, I then lose everything??

[a10 gf]

^^^ Looks like you have some interesting archeological (electrological :O) digging to do.

Ref my previous post, be sure the regulator is not the problem source, get it out of the equation. Did you do tests with regulator disconnected?

Do you have a voltmeter? If not, get one. Use it to find excatly where the power loss occurs.
Start at the battery. If getting constant voltage there during a blackout, move along according to the wiring diagram.

it's not been quite as catastrophic as now
That's 'good', as the more often it happens (or getting constant) it will give you better opportunity\time to find the fault :O)

[Worty]

Just one other piece of info which may help.

Previously, when I've turned the lights on, they switched on dim then, after about 5-10 seconds they came on full as normal???  I'm seriously not making this up.  Before that, I would lose the headlamp only but it came on after I turned it to full lock on the left hand side.  I checked then for wiring problems and found none.

Looks like I'm going to have to do as advised and work from the regulator/battery onwards - hopefully I'll sort it before the next riding day!!

[Slippery Sam]

Did you do anything before this happened - added wires, adjusted your horn, changed regulator, or even just had the battery off for charging?  If so go back to that (and un-do if needed).  You mentioned charging the battery - was this because it went flat in normal use?
One suggestion was to eliminate the reg.  Alternatively you could check if the reg is working (6V +) accross battery.
As well as wiggling wires:
check all connectors (there aren't many) - have a good look, clean each and grease (electrolite). Also do this with earths - remove clean re-fit.
If reg has been on and working for a while - it shouldn't be reg wiring - but I'm sure on my Wassel solid state reg (+ earth 6V) - the loom Black goes to reg red and loom purple goes to reg black - which is a bit counter intuitive (I could be wrong here so someone correct me please).

Also headlamp and turning handlebars issues - does that not narrow it down a bit to wires going in and out of the headlamp casing?  There should be a few earths inside too (headlight fitting, switch casing and an-other).  Also a chance of chaffing where wires go in and out.

I'm not an A10 authority and still learning - but wiring is wiring - a lot of the time a bad connection can cause all sorts of issues.

Good luck and keep us posted.

[Worty]

Thanks for all the info coming in.

I hadn't done anything to the bike that I could undo, although I did change the battery to a Westco because the old lead acid item was faulty.  I know vibration can kill batteries quickly, so changed to Westco as they came highly rated.

Regarding the regulator, when the electrics are working the bike charges really nicely (especially after cleaning the commutator and brushes).

I would agree about the headlamp issues and turning the handlebars, but I've already had everything apart and checked connections.  I guess I'll need to get the seat and tank off and just go through everything systematically.  The electrics have been crap on the bike since day 1, despite having a new loom and having it professionally fitted!!

[metalflake11]

Check the fuse holder, mine packed up this year, and to look at it you'd never know it was defunct. Intermittent problem just like yours.

[Worty]

Errr wot fuse holder???

By the way, I've pulled out an old mutimeter which I've never used so I've looked up some instructions.  It's very simple but, according to the instructions, to test continuity I set the switch to the lowest ohms setting and hook it up to the circuit I want to test.  If the reading is low, continuity is there, if it's high, there's a problem - does this seem right to you?

[metalflake11]

Dear me!...........New loom, professionally fitted, and no fuse! Poor show that.

If you're near Manchester I'll re-wire it/sort it out at cost for you.

Can't help with your multi-meter question I'm afraid.

[Worty]

Cheers metalflake11, really appreciate the offer!  I'm across the M62 at Wakefield so a bit of a jaunt unfortunately.  Also, I'm wanting to get to grips with the vagaries of old British iron electrics, so I'll persevere for now keeping the lump hammer in a locked box!!

Must admit that when the fuse wasn't put in I was a bit surprised - was told I wouldn't need it as it wasn't on originally and never really presented any problems for the 6v system???

I'm going to give the electrics a mauling this weekend and will let you know what I come up with - if anything.  The only question I have at present is whether to fit additional earths as I understand that my machine struggles to earth through the headlamp cowl because it has to pass through the ball bearing grease on the yokes?!